Since different protein sources have distinct amino acid profiles and utilization rates, Natural Pro Complex Augmented Protein System (APS) combines 8 sources to create a superior protein blend, designed to enhance your muscle building potential. Uniting Whey Protein Isolates, Egg Albumen, Hydrolyzed Proteins, and key Free Form Amino Acids, Optimum Nutrition has created a protein with varied digestion rates and an amino acid profile that's off the charts. Each serving of Natural Pro Complex APS is packed with 60 grams of the highest quality proteins commercially available. Natural Pro Complex is also free of artificial flavors, sweeteners, and synthetic colors. So naturally, it's formulated to take you to the next level.